Heterodera avenae (Cereal Cyst Nematode)

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cyst nematode

The term Heterodera (Cyst Nematode) derived from Greek words.

Heteros: Different

Deros: skin or body wall

  • Heterodera or cyst nematodes comprise many genera: Heterodera, Globodera, Punctodera.
  • Because of the shape of adult female containing numerous (about 400) egg called cyst nematode.
  • The species of Heterodera designed after host specificity.
  • Host are cereals:- Heterodera avenae, Soya bean:- Heterodera glycenes, Brassica:- Heterodera cruciferal
  • Host pigeon pea: Heterodera cajani

Systematic Position:-

PhylumNematoda
ClassSecernentea
OrderTylenchida
FamilyHeteroderidae
GenusHeterodera
Speciesavenae

Diagnostic Features:-

Female and Cyst stage:-

Cyst nematode
  • Female sedentary, endoparasite in root (Meristmatic and Cortex)
  • Vulva terminal, vulval fenestration present.
  • Anus subterminal placed dorsally oesophagus gland present but not well developed.
  • Cyst lemon shape with cap in both extremity.

Diagnostic Features of Male Heterodera:-

heterodera
  • Male vermiform, slender, elongated about 1mm in length.
  • Tail twisted.
  • Spicules one pair and robust.
  • Gubernaculum present.
  • Anus subterminal.

Host and Distribution:-

  • The major hosts for Heterodera average are wheat, barley, oat.
  • They are worldwide in distribution.
  • But in India majorly found in Haryana and Rajasthan.
  • They are economically importance and causes a disease “Molya” in Wheat and Barley.
  • But they are reported form Uttar Pradesh, MP, Maharastra, Punjab, and Delhi.

Read More:– Pratylenchus penetrans (lesion Nematode) Click Here

2nd stage juvenile:-

  • These are vermiform, elongated worms about 0.4-0.6mm in length.
  • Body sclerotized, with tapering glistening tail.
  • Oesophagus present, oesophageal gland overlapped ventrally to the intestine.
  • No, any reproductive organs.
  • These are infective stages.
  • It moults three-time and gives rise to adult organism.
  • They do not retain their cuticle during moulting.
  • Stylet was more robust than other nematodes (Root-knot nematode).

Read More:Reniform Nematodes (Rotylenchulus Nematode) Click Here

Life cycle & Biology of Cyst nematode:-

  • These are sedentary endoparasites in the root.
  • Adult female in cyst form, while male in vermiform elongated.
  • Adult female after oviposition dies in few days.
  • cuticle turns brown to black color cyst containing numerous eggs about 400 in Heterodera.
  • These cyst remains in the soil or attached to root during off-season (April).
  • Eggs start maturation inside eggs up to November.
  • During November due to the extrinsic stimulus (temperature) or root exudes they start hatching.
  • These eggs hatch 1st stage juveniles and later on turns in 2nd stage juvenile (infective juvenile stage).
  • The most favored zone of root for nematode infection is the meristematic zone.
  • These iJs moulted three time and give rise to adult individual.
  • Intermediary stage are 3rd –4th stage juveniles.
  • Adult male emerges from 4the stage cuticle and start moving forward female.
  • They reproduce sexually but sometimes may be parthenogenetically.
  • Fertilized female starts egg laying in mouth of jan- feb after oviposition dies.

Read More: Anguina tritici (wheat seed gall nematode) Click Here

Symptoms of Cyst Nematode :-

  • Bushing rooting
  • Premature flowering.
  • Head ears bear fewer grains.

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